Arrangement for closing test tubes



May 8, 1962 A. JQUDA ARRANGEMENT FOR CLOSING TEST TUBES Filed Dec. 8, 1959 .vieil States 3,033,408 Patented May 8, 1962 3,033,408 ARRANGEMENT FOR CLOSING TEST TUBES Andr Jond, 8 Rue du Plat, Lyon, France Filed Dec. 8, 1959, Ser. No. 858,156 Claims priority, application France Dec. 10, 1958 4 Claims. (Cl. 21S-56) The present invention relates to a closing device for a test tube.

It is well known to close tubes containing culture media for the multiplication of bacteria and for the investigation of fermentation procedures by carded cotton. This closure enables the exchange of gases between the inside of the tube and the atmosphere. Gases are produced by bacterial metabolism of the foodstuff formed by the culture medium, which gases are replaced by the oxygen and nitrogen of the atmosphere. 'Ihese exchanges prevent asphyxia of the bacteria which would occur in certain cases with a fluid-tight closure. Furthermore, the handling of cotton wool Stoppers is easy and speedy. However, the carded cotton cannot maintain fluid-tightness so that storage of the culture media for future use requires concentration thereof to compensate for the lack of fluidtightness of the cotton.

The lack of fluid-tightness allows the formation of molds which contaminate the culture media. This is especially true when the culture medium contains sugars. Furthermore, cotton wool Stoppers do not seal the tube, thereby making handling and transportation extremely difiicult.

It is an object of the invention to provide a closing device which eliminates the above-noted deficiencies.

It is a further object to insure isolation of the culture medium to protect it against bacterial contamination while maintaining the initial composition thereof.

It is a feature of the invention to selectively permit the connection between the inside of the tube and the atmosphere, the connection being established in an aseptic manner, to allow for an exchange of gases and any desired evaporation. The handling of the improved arrangement is also convenient and does not require any modification of the usual movements of the biologist when opening and closing bacteriological tubes.

it is a further feature of the invention to provide an aseptic connection between the inside of the tube and the outer atmosphere, which connection is adjustable to effect complete sealing of the tube.

The closing device, according to the invention, includes a stopper provided with an axial bore which does not open axially at its upper end and is connected with one or more transverse recesses which open laterally into the peripheral surface of the stopper. A filtering plug of cotton, glass bers or expanded plastic material is provided in the connection between said recesses and the bore. According to a further feature of the invention, the recesses are positioned at the periphery of the stopper such that, the exposure of the recess is controlled according to the extent of introduction of the stopper inside the test tube.

Furthermore, and in accordance with a preferred embodiment, the axial Ibore in the stopper may carry at its free lower end a removable faucet, the central bore of which has a very small diameter and extends throughout the height of said faucet. This faucet is particularly useful when the culture medium contained within the tube is a liquid, since it prevents any exaggerated imbibition of the cotton or the like filtering plug, which might lead to serious drawbacks during the subsequent successive closing and opening operations of the faucet.

The narrow channel in the faucet bore opposes the progression of the liquid culture up to the filtering plug without interfering with the exchange of gases between the inside of the tube and the atmosphere.

It is necessary to prevent any exaggerated projection of said faucet inside the stopper bore, which would compress the filtering plug such that the plug would be urged int'o the lateral recesses and therefore reduce its effectiveness as a bacteriological filter. Accordingly, the faucet cannot extend inside the central bore of the stopper beyond a predetermined point.

Furthermore, to facilitate insertion and removal of the stopper, an upper inverted skirt-shaped extension is formed to provide a semi-yielding grip.

The invention will lbe readily understood upon reading of the following description, reference being made to the accompanying drawings illustrating a preferred embodiment, given by way of example. In said drawings:

FIG. 1 is a lateral elevational view of the improved closing device.

FIG. 2 is an elevational sectional view through line 2 2 of FIG. l and including a test tube.

FIG. 3 is an elevational sectional view at 90 of FIG. 2, along line 3 3 of the latter.

FIG. 4 is a plan view through line 4 4 of FIG. 2.

According to the drawings, the closing device consists of a stopper 2 made of rubber or of any yielding or semiyielding plastic material and which is provided with an axial bore 3, opening at its upper end inside a transverse chamber 4 forming two lateral recesses 5 and 6 opening respectively into the side wall of the stopper 2. An extension which comprises a shank 7 terminated with a peripheral bead 8 caps the plug and enables inserting and removal of the plug from the test tube.

A filtering plug 9 of carded cotton wool, glass fibers or the like, is inserted inside the axial bore 3 and is urged inwardly until it is in the transverse chamber 4.

In the case where the plug is intended for use with a liquid cult-ure medium, a faucet 10 provided with an axial Y channel 11 of a small diameter is fitted inside the axial bore 3. The degree of penetration of said faucet is limited by a shoulder 12 formed along the edge of the connection between the chamber 4 and the bore 3 in the stopper.

It is apparent, from inspection of the drawings, that, according to the depth of insertion of the stopper inside the test tube 13, the upper edge of said tube may be beneath the recesses 5 and v6, as illustrated in solid lines in FIG. 2, or may partially close the recesses and the chamber 4, or may entirely close the recesses as illustrated in dotted lines in FIG. 2. Consequently, the depth of penetration of the stopper controls the exposure of the culture medium in the tube to the atmosphere.

Obviously, and as already mentioned, the invention is by no means limited to the embodiment disclosed and it covers all the modifications thereof falling within the scope of the accompanying claims:

What I claim is:

l. A sealing device in combination with a test tube comprising a stopper provided with a lateral recess therethrough, said stopper being inserted to a determinable depth in the test tube and providing a seal therebetween, said lateral recess having an exposure controllable by the depth to which the stopper is inserted in the tube, said stopper in said tube defining a closed portion in'said tube, said stopper being provided with a bore between said closed portion of the tube and said recess, and a filter in said recess surrounding said bore to provide an aseptic condition in the closed portion of the tube.

2. The combination as claimed in claim l further com-V prising a removable faucet in said bore to provide a seal between the faucet and the stopper, said faucet having a passageway therein between the recess and the closed portion of the tube.

3. The combination as claimed in claim 2, wherein said 3 4 stopper is provided with a shoulder at said bore to limit References Cited in the tile of this patent the penetration Of the faucet in the SOPPQ'. UNITED STATES PATENTS 4. The combination as claimed in claim 3, further 2 comprising an extension on sald stopper, said extension 919,961 Schuman Apr' 2 including a shank portion having an end of determinable 5 2655280 Omen Oct' 13# 1953 size and a bead portion of larger size on said end portion,

whereby said extension provides a gripping portion for the FOREIGN PATENTS plug. 1,057,483 Germany May 14, 1959 

